If you are using and older version of Windows with NTFS then I can send you an "ln" executable (or the source code for it in c++) that I whipped up years ago (just calls the API function to make a hard link - note that being a hard link the other logical drive must be on the same physical hard drive)...
Had you tried that yourself you'd know that bitcoin client crashes when using hard-linked directories.Try your own tool or grab Sysinternals Junction
from Microsoft and for crying out loud test your advice before posting.
Well I only mentioned a tool rather than what to do with it actually - the advice I would have given (if he was interested in the tool at all) would be to hardlink to the large file rather than to a directory and I *know* Bitcoin works with that because that is how I use it.